Photographic emulsion



Patented July 11,1939

UNITED STATES PATENT (lf-'FICE'.

PHOTOGRAPHIO EMULSION Leslie G. S. Brooker, Rochester, N. Y.,

assignor to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey Application September 16, 1936, Serial No. 101,105

Claims.

' This invention. relates to hemioxonol dyes and photographic emulsions containing the same.

Dyes of the cyanine class and dyes of the merocyanine class are known to alter the sensitivity of photographic emulsions, particularly photograhic silver salt emulsions. -Now, I have found that dyes of the hemioxonol class alter the sensitivity of photographic emulsions. new and heretofore-unknown dyes of the hemioxonol class. The object, therefore, of my in.

vention is to provide photographic .emulsions containing dyes of the hemioxonol class. A further object is to provide new hemioxonol dyes and a process for the preparation thereof. Other canbe represented by the following general formula:

wherein A represents a divalent non-metallic atom, such as oxygen or sulfur, n represents a positive odd integer, R represents hydrogen, an alkyl group or an acyl' group, R represents an aryl group and Z represents the non-metallic atoms necessary to complete a five-membered or six-membered heterocyclic nucleus.

More particularly R can represent an alkyl group, such as methyl, ethyl or n-butyl, or an acyl group, such as' acetyl, propionyl or benzoyl. R' can representan aryl group such as phenyl, chlorophenyl, diphenyl or naphthyl. Z can represent the non-metallic atoms necessary to complete a thiazolone, an oxazolone, an imidazolone, a pyrazolone, a thioindoxyl or like nucleus. Examples of thiazolone nuclei are: a 2,4(3,5)thi azoledione nucleus, or its nitrogen substituted derivatives, e. g.`N-alkyl or N-phenyl derivatives, a 2-thio2,4(3,5) -thiazoledione nucleus, i. e. rhodanine or its nitrogen substituted derivatives, e.` g. 3-alkyl-rhodanines, 3-phenylrhodanines, 3-naphthylrhodanines, 3-pyrazolonylrhodanines, a 2,4- dithio-2,4(4,5)-thiazoledione nucleus, or its nltrogen substituted derivatives, a 4-thiazo1edione nucleus 'or its nitrogen substituted derivatives, a 2-substituted-mercapto4(5) -thiazolone nucleus such as a 2alkylmercapto-4(5) thiazo1one,

I have also found or a 2-substituted-amino-4i5)-thiazolonenucleus, such as a.l 2-dia1kylamino-fi(5) -thiazolone, a 2alkylphenylamino-4(5) -thiazoloneor a 2-dipheny1amino-4(5)-thiazolone. Examples of oxazolone nuclei are: a 2-thio-2,4(3,5)oxazoledi one nucleus.l Examples of imidazolone nuclei are: hydantoin or its nitrogen substituted derivatives, e. g. N-allwl or N-phenyl derivatives, 2-thlohydantoin or its nitrogen substituted derivatives or a 2-substituted-mercapto-5(4)-imidazolone, such as a 2-alkylmercapto-5(4)-imidazolone. Examples of pyrazolone nuclei are: l-phenyl-3- alkyl- 5 -thiopyrazclone, 1 -naphthyl- 3 -alkyl-5- 'thiopyrazolone and 1-phenyl-3-jalky1-5-pyrazolone. Z can also represent the non-metallic atoms necessary to complete a barbituric acid (2,4,6triketohexahydropyrimidine), 2thiobarbi turi'c'acid, a 1,3-dihydroxyquinoline, dihydrocarbostyrill, oxydihydroquinoxalin,

bered nuclei. All of the above veand six-membered nuclei are derived from heterocyclic compounds containing a nuclear methylene group adjacent to a nuclear carbonyl or thiocarbonyl group, i. e. heterocyclic compounds characterized by the nuclear grouping:

CHz-(lJ=A j wherein A represents oxygen or sulfur.

When n represents one in the above formula the dyes contain a chain of one methenyl group (-CH=) and are conveniently referred to as hemicarboxonol dyes, when n represents three the dyes contain a chain of three methenyl groups (-CH=CH-CH=) and are conveniently referred to as hemidicarboxonol dyes, and when n represents ve the dyes contain a chain of five methenyl groups (-CH=CHCH=CHCH- V) and are'conveniently referred to as hemitricarboxonol dyes.

Members of the hemicarboxonol group are known and have been described by Dains et al. See for example J. Chem. Soc. 31, 1148 (1909); 44, 2310 (1922) and Kansas Univ. Science Bull. 15, 265 (1924); 19, 215 (1930). lHemicarboxonol dyes from pyrazolones have also been described by Rodd and vWatts in British Patent 366,964. Hemicarboxonol dyes can be prepared by reacting a diarylformamidine with a heterocyclic compound containing a nuclear methylene group adjacent to a nuclear carbonyl or thiocarbonyl group. Diarylformamidines which can be used are for example, diphenylformamidine, dinaphthylformamidine, dixylylformamidine or the like. The following examples serve to illustrate the benao-,B-mor-v pholone, homophthalimide or the `like six-mem amples are not intended to limit my invention.

3.2 g. (1 mol.) of 3-ethylrhodanine, 3.9 g. (1 mol.) of diphenylformamidine and 15 cc. of kerosene were heated under reux at about 120 C. The reaction product separated from the warm reaction mixture. The reaction mixture was chilled and the product ltered oi and washed with cold methyl alcohol. The product was recrystallized from glacial acetic acid. The compound has the following formula:

II C This compound can be converted into -acetanilidomethylene-3-ethy1rhodanine by refluxing 1.3 g. (1 mol.) thereof with 10 cc. of acetic anhydride and 0.5 g. (1 mol.) of triethylamine for about minutes. The acetanilido derivative separated from the cooled reaction mixture and after two recrystallizations from methyl alcohol was obtained as pale yellow crystals, melting at 12S-130 C. The acetanilido compound has the following formula:

Equimolecular proportions of 3-ethyl-2-thio-2, 4(3,5)oxazo1edione and diphenylfornamidine were treated as in Example l. The product was recrystallized from methyl alcohol.

This compound can be converted into 5-acetanilidomethylene 3 --ethyl 2 thio 2,4 (3,5) oxazoledione by heating 8.7 g. (1 mol.) thereof with 30 cc. of acetic anhydride and 3.7 g. (1 mol. of triethylamine at about 100 C. for about 10 minutes. The acetanilido derivative separated from the cooled reaction mixture and after two recrystallizations from methyl alcohol was obtained as 2,185,389 vpreparation of hemicarboxonol dyes. These exnearly colorless crystals melting at G-160 C. 'Ihe acetanilido compound has the following formula:

`can be prepared by reacting a heterocyclic compound containing a. nuclear methylene group adjacent to a nuclear carbonyl or thiocarbonyl group with a compound of the formula:

R-NH-CH=CH-CH=NR wherein R and R' represent aryl groups such as phenyl, chlorophenyl, diphenyl, naphthyl or the like. Such latter compounds can be referred to as arylamino acrolein anils and are advantageously employed in the form of their salts, such as their hydrochlorides. When the arylamino acrolein anils are employed in the form of their salts, the reactions are aduantageously effected in the presence of a strong organic base, such as triethylamine, piperidine, N-methyl-piperidine, triethanolamine, diethylamine or the like. Weaker organic bases such as pyridinel can be used. The reactions can be eieoted using arylamino acrolein anils or their salts, in the presence of acetic anhydride or acetic anhydride and potassium or sodium acetate. Propionic or butyric anhydride can also be used.

The following examples serve t illustrate the preparation of hemicarboxonol dyes. These examples are not intended to limit myv invention.

Example 4.--5- (y-acetanilidoallylidenef) -3- ethylrhodanine 3.2 g. (1 mol.) of 3-ethylrhodanine, 5.2 g. (l mol.) of -anilinoacrolein anil hydrochloride and 30 cc. of acetic anhydride were heated under reflux for about one hour. The compound separated from the cooled reaction mixture and after two recrystallizations from methyl alcohol was Y obtained as pale yellow crystals melting at 225.5-226.5 C. The compound has the following formula:

eithylrhodanine l thepresence of 'triethylamina' See Example 1.

tained as garnet crystals with a blue reflex. Th compound has the'following formula:

This compound can be converted into the acetylated form by treating with acetic anhydride in This compound can be converted into the acetylated form by treating with acetic anhydride in the presence of triethylamine. See Example yl.

2.1 g. 2 mol.) of s-pnenyirncdanine, 1.9-1 (i mol.) of -anilino-a-bromo-acrolein anil hydrobromide and l0.64; g. (1.5 mol.) of piperidine were allowed to react at room temperature for about 20 hours. The compound separated from the reactionlfzixture and after recrystallization from glacial acetic acid wasobtained as reddish brown needles. The compound has the following .for-

mula:

Example 8.-.-- ('y-anlinoallylidene) -3- etnyzrhcdanme 0.8 g. (2 mol.)` of 3-ethylrhodanine, 0.62 g. (1

' mol.) of -anillnoacrolein anil hydrochloride and 0.21 g. (1 mol.) of piperidine were allowed to react at room temperature for about 21/2 hours.

' The compound separated from the reaction mixture and a'fterrecrystallization from methyl alpound hasl the following formula:

lco'hol was obtainedasv garnet crystals. The comazolone, 2.6 g. (1 mol.) of -anilinoacrolein anill hydrochloride and 20 cc. of acetic anhydride were heated to'refluxing for 30 minutes. The compound separated from the cooled reaction mixture. After two recrystallizations from methyl alcohol, the compound was obtained .as minute yellow crystals melting at 265267 C2.-

Example 10.-5 ('yanilidoallylidene) -3- ethyl- 2,4(3,5) -oazazoledlone 2.9 g. (1 mol.) of 3ethyl-2-thio-2,4(3,5) -oxazoledione, 5.2 g. (1 mol.) of -anilnoacrolein and hydrochloride, 30 cc. of absolute ethyl alcohol and 2.0 g. (2 mol.) oftriethylamine were heated to refiuxing for about 30 minutes. The compound vseparated from the cooled reactionl mix` ture. This compound can be acetylated .as follows: 5.8 g. (1 mol.) of 5-(1-ani1ido-allylidene) -3-ethy1- 2-thio-2, 4(3,5) -oxazoledione, 30 cc. of acetic an' hydride and 2.0 g. (1 mol.) of triethylamine were heated to refluxing for about 5 minutes.y The product separated from the cooled reaction mixture. After two recrystallizations from' methyl alcohol, lthe product was obtainedas minute green,

ish yellow crystals, melting at 247249 C. with'. v

decomposition. The acetylated product has the following formula:

4.6 g. (1 mol.) of 1-benzothiazylv-3-methyl-5- pyrazolone, 5.2 g. (1 mol.) of anilino-acrolein anil hydrochloride and 25 cc. of acetic anhydride were 'heated to reuxing for 10 minutes. Thel product separated from the cooled reaction mixture. The product has the following formula:A

` OCCHI Example 1.2.-5-(1-ani1ido-azzyziaene)-s-ethyz-1-- l phenyl-Z-thiohydantoin 4.49 g. (l mol.)l of 3ethyl1-phenyl-2-thiohydantoin,.5 g. (1 mol.) of -anilino-acrolein anil hydrochloride, cc. absolute ethyl alcohol and 2.0 g. (1 mol.) of triethylamine were reuxed for about 30 minutes. The product. separated from the cooled reaction mixture.

This compound can be acetyiated as follows: 1.75 g. (1 mol.) ofthe anilido compound.. 10 cc. of acetic anhydride and"1.5g. (1 mol.) of triethylamine were heated vfor about 15 minutes. The

product separated from the cooled reaction mixture. After two recrystallizations from methyl alcohol it was obtained as yellow crystals. melting at 18421869 C. with decomposition. The

acetylated compound has the following formula:

Example 13.-4- (-y-acetanizido-alzyzidene) 3 methyl-1-phenyI-S-pyrazolone `3.5 g. (1 mol.) of 3-methyl-1-phenyl5pyra zolone, 5 g. (1 mol.) of -anilinoacrolein anil hydrochloride, 20 cc. of acetic anhydride and 2 g. (1 mol.) of triethylamine were reuxed for about 30 minutes. The product separated from the cooled reaction mixture. After two recrystallizations from methyl alcohol, the product was obtained as iiaky orange crystals, melting at 212-214 C. 'I he product has the following formula:

In a manner similar to that illustrated in the above ten examples other heterocyclic compounds containing a. nuclear methylene group adjacent to a nuclear carbonyl or thiocarbonyl group can be reacted with arylamino acrolein anils to give hemidicarboxonol dyes. Examples of such other heterocyclic compounds correspond to the veand six-membered heterocyclic nuclei named in connection with the above general formula for these hemioxonol dyes.

Members of the hemitricarboxonol group were heretofore unknown and I have'found that they can be prepared by reacting a veor sixmembered heterocyclic compound containing methylene group, a nuclear methylene group adjacent to a, nuclear carbonyl or thiocarbonyl group, with a compound of the following formula:

wherein R and R! represent aryl groups, such as phenyl, chlorophenyl, toluyl, diphenyl, or naphthyl groups. Such compounds are advantageously employed in the form of their salts, such as their hydrochlorides. Such compounds can be referred to as w-arylamino-A2,4pentadienal anils. When employing the salts of the anils the reactions are advantageously carried out in the presence of a strong organic base, such as triethylamine, piperidine, diethylamine, triethanolamine or N-methylpiperidine. Weaker organic bases such as pyridine can be used. The reactions canalso be carried out employing the anils or their salts in the presence of acetic anhydride or acetic anhydride and sodium or potassium acetates. Propionic and butyric anhydrides can also be used.

The following examples serve to illustrate the prepartion of hemitricarboxonol dyes. These examples are not intended to.limit my invention.

Example 14.--5- (w anilino 12,4 pentadienyl- -idene) -3phenyl-2,4 (3,5) -thiaaoledicme 1.93 g. (2 mol.) of 3phenyl2,4-thiazoledione, 1.43 g. (1 mol.) of glutaconic aldehyde dianilide hydrochloride and 0.45 g. (1 mol.) of piperidine were allowed to react at room temperature in absolute ethyl alcohol (50 cc.) for about 161/2 hours. 'I'he compound separated from the reaction mixture and after recrystallization from methyl alcohol was obtained as reddish brown plates. The compound has the following formula:

3.2 g. (lmol.) of 3-ethylrhodanine, 5.6 g. (l mok) of glutaconic aldehyde dianilide hydrochloride, 40 cc. of absolute ethyl alcohol and 2 g. (1 mol.) of triethylamine were heated to reiiuxing for about three minutes. The compound separated from the cooled reaction mixture. The compoundwas heated to boiling with 50 cc. of acetic anhydride to produce the acetanilido derivative. The acetanilido derivative has the following formula:

In a. manner similar to that illustrated in the above two examples other heterocyclic compounds containing a nuclear methylene group adjacent to a nuclear carbonyl or thiocarbonyl group can be reacted with w-arylaminoA2,4-pentadienal anils to give hemitricarboxonol dyes. Examples of such other heterocyclic compounds correspond to the veand six-membered heterocyclic nuclei named in connection With the above general formula for these hemioxonol dyes.

I have further found that dyes similar in some respects to these hemioxonol dyes can be prepared by reacting diarylformamidines, arylamino acrolein anils or arylamino glutaconic aldehyde anils with homocyclic compounds containing a nuclear methylene group adjacent to a carbonyl or thiocarbonyl group as well as with open chain compounds containing a methylene group adjacent to a carbonyl or thiocarbonyl group. In other words, I have found the reaction to be a very general one and capable of wide application. 'I'he reaction can be carried out as illustrated in the above fifteen examples. Examples of homocyclic and open chain compounds which will undergo reactions are: 1,3-cyclohexadione, benzoylaceto-nitrile, cyano-acetanilide, malonic acid or its esters, pyruvic acid or its ester, acetoacetic ester, benzoyl-acetone, acetylacetone, indandione or the like. The following example illustrates the preparation of a dye from benzoylacetonitrile.

Erample 16.-a (yamldoallyldene) -benzoylace- 'f tonitrile 1.45 g. (1 mol.) of benzoylacetonitrile, 2.5 g. (1 mol.) of -anilinoacrolein anil hydrochloride, 20 cc. of absolute ethyl alcohol and 1.0 g. (l mol.) of triethylamine were refluxed for about 30 mintites. The product separated from the cooled reaction mixture.

This compound can be acetylated as follows: 5.5 g. (1 mol.) of theanilido compound, 40 cc. of acetic anhydride and 2.0 g. of triethylamine were heated at 100 C. for about 10 minutes. The acetylated product separated from the cooled reaction mixture. After two recrystallizations from methyl alcohol, the product was obtained as l my invention is directed to the customarily emn yellow needles melting at 208210 C. with decomposition. 'I'he acetylated product has the following formula: l

Some of these dyes from homocyclic and open chain compounds alter the sensitivity of photoparticularly silver halide emulsions.- Accordingly,

ployed silver halide emulsions. However, the light-sensitive material employed in the emulsions of my invention canbe any light-sensitive silver salt alone or combined with another silver s salt,v such as a silver halide. Myinvention is further particularly dir'ected'to the customarily employed gelatin emulsions, gelatin being the carrier or medium in which the light-sensitive salt is suspended. However, any other suitable. carrier, such as a cellulose derivative or a` synthetic resin, which has substantially no desensitizing effect on the silver salt can be used.

The alteration in sensitivity produced by these hemioxonol dyes will be illustrated with particular reference to gelatino-silver-chloride and bromide emulsions, since itis in these emulsions that the dyes have been found to be most useful. 'I'he dyes containing `the shorter chain of methenyl groups are generally most useful in silver chloride emulsions. The illustrations will be made with particular reference to the hemicarboxonol dyes and hemidicarboxonol dyes as the results obtained with dyes from these two groups are most useful.

Fig. 1 of the accompanying drawings illustrates diagrammatically the sensitivity of agelatinosilver-chloride emulsion containing 10 mg.' of 5- anilidomethylene-3-ethylrhodanine per liter of .emulsiom Fig. 2 a gelatino-silver-chloride emulsion containing 10 mg. of 5acetanilldometh ylene-B-phenylrhodanine per liter of emulsion; Fig. 3 a gelatino-silver-chlorlde emulsion con. taining 10 mg. of 5anilidomethylene-S-ethyl-2- thio2,4(3,5)-oxazoledione per liter of emulsion; Fig. 4 a gelatino-silver-chloride emulsion containing 10 mg. of 5-(fy-acetanilidoallylidene-1,3- diphenyl-Z-thiohydantoin perN-liter of emulsion; Fig. 5 a gelatino-silverfchloride emulsion containing 10 mg. of 5- f-anilidoallylidene).--ethyle rhodanine per liter of emulsion; Fig. 6 a'gelatinosilver-bromide emulsion containing l mg. of 4- (y-anilidoallylidene) 1benzothiazyl3-methyl-5- pyrazolone per liter of emulsion; Flg..7 a gelatino- -silver-chloride emulsion containing 10 mg. of`5- ('y-anilidoallylidene) -3-ethyl-l-phenyl-2-thiohydantoin per liter of emulsion; and Fig. 8 a gelatino-silver-bromide emulsionV containing 10 mg'.v of (fy-anilido--bromfallylidene) -3-phenylrhodanine per liter of emulsion.S As is well known in the art of emulsion making, dyes are conveniently incorporated in emulsions by adding to the emulsion a solution of the dye in an appropriate solvent.

' The herein described dyes may be substituted on the nuclei with groups such as alkyl, -alkoxyl, chloro, brpmo, amino or the like. Some of the herein described dyes show small desensitizing eilects together with sensitizing elects in another range of the spectrum.

The herein disclosed dyes are also useful in the construction of light lters' and vas coloring matters for textiles, particularly cellulose acetate silk or the like.

It is to be understood that the herein disclosed dyes probably exist in two forms, to wit:

As illustrated these forms are interconvertible' one intothe` other, i. e. the forms are virtual tautomers.

What I claim as my invention and desire to be secured by `Letters Patentof the United States of America'is:

1. A photographic'silver salt emulsion containing a. sensitizing dye selected from the grOllD of dyes characterized by the following formula:

lwherein A represents an atom selected from the the non-metallic atoms necessary to complete a heterocyclic nucleus -selected from the group consisting of iive-membered and six-membered heterocyclic nuclei.A

2. A photographic silver halide emulsion containing a sensitizing dye selected from the group of dyes characterized by the following formula:

R-1-|I(cH)..=d-=A wherein A represents an atom selected from the A group consisting of oxygen and sulfur, n represents a positive odd integer not greater than ve, R represents a substituent selected from the group consisting ofv hydrogen. alkyl lgroups and acyl groups, R' represents an aryl group selected from the group consisting of aryl groups oi' the lbenzene and naphthalene series and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the groupconslstlng of flve-membered and six-membered heterocyclic nuclei.

3. A gelatino-silver-halide emulsion containing a sensitizing dye selected from the group of dyes characterized by the following formula:

' /Z\ v a-rr-(omF-Aoi Rl. wherein A represents an atom selected from the group consisting of oxygen and sulfur, n represents a positive odd. integer not greater than five, R `represents a substituent selected fronithe group consisting of hydrogen, alkyl grou and acyl groups, R.' represents an aryl group s. from theI group consisting of.aryl groups of the benzene and naphthalene series and Z represents lected heterocyclic nucleus selected from the group consisting of ve-membered and six-membered heterocyclic nuclei.

4. A gelatino-silver-halide emulsion containing a sensitizing dye selected from the group of dyes characterized by the following formula:

wherein R represents a substituent selected from the group consisting of hydrogen, alkyl groups and acyl groups, R represents an aryl group selected from the group consisting of aryl groups of the benzene and naphthalene series and Z represents the non-metallic atoms necessary to complete a 3-alkyl-2,4(3,5) -oxazoledione nucleus.

6. A gelatino-silver-halide emulsion containing a sensitizing dye selected from the group oi. dyes characterized by the following formula;

. /z R-1I-oH=cH-oH=d-=o wherein R represents a substituent selected from the group consisting of hydrogen, alkyl groups and acyl groups, R represents an aryl group selected from the group consisting of aryl groupsv of the benzene and naphthalene series and Z represents the non-metallic atoms necessary to complete a 2-diphenylamino4(5) -thiazolone.

7. A gelatino-silver-halide emulsion containing a sensitizing dye selected from the group of dyes characterized by the following formula:

, /z\ `n-N-cH=cH- :H=d--i3=o if,

wherein R represents a substituent selected from the group consisting of hydrogen, alkyl groups and acyl groups, R. represents an aryl group selected from the group consisting of aryl groups of the benzene and -naphthalene series and Z represents the non-metallic atoms necessary to complete a 1-benzothiazyl-3-methyl--pyrazolone nucleus.

8. A gelatino-silver-halide emulsion sensitized with (ry acetanilido-ally1idene)2 diphenylamino-4 5) -thiazolone.

9. A photographic gelatino-silver-halide emuly sion sensitized with 5-('y-acetanilido-allylidene) S-ethyl-'ZA (3,5) -oxazoledione.

10. A'` photographic gelatino-silver-halide emulsion sensitized with 4 (fy-acetanilido-allylidene) l-benzothiazyl-3-methyl-5-pyrazolone- LESLIE G. S. BROOKER. v 

